Paving roller



June 17, 1930. w, LASTER 1,764,963

PAVING ROLLER Filed March 13, 1929 Zn enivr:

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Patented June 17, 1930 UNITED STATES HARRY W. LASTER, OF OAK PARK, ILLINOIS PAVING ROLLER 7 Application filed March 13, @1929. Serial No. 346,537.

This invention relates to paving rollers, and its principal object is to provide a paving roller having novel means whereby a more efi'icient pavement may be obtained than heretofore. The ordinary paving roller has front smooth faced rolls which act to crush material andsmooth it as the roller is moved back and forth thereon, but the roller has a tendency to push the paving material forward in of the roller with the result that a great number of fissures or cracks occur in the pavement. A

Furthermore, it is practically impossible for the workmen to spread the paving material evenly in front of the roller and ofttimes the material presents high spots or relatively hard places which prevent the roll from bearing down equally along its length on the surface which is being rolled down, thus resulting in a honeycombed structure. Water seeps into the cells of the honeycomb structure and into the cracks and fissures which causes the pavement at those places to deteriorate rapidly with the result that the c soon breaks up the pavement forming rough ragged holes therein.

n accordance with the present invention, I provide the paving roller with a roll having circumferential corrugations which act to break up and crush the harder material and to spread the same laterally instead of piling it up in front of the roll. The invention consists, therefore, in a paving roller having .a circumferentially corrugated paving roll.

It further consists in a paving roller having a circumferentially corrugated paving roll at one end and a smooth paving roll at the other end. It further consists in a paving roll having smooth paving rolls and an auxiliary circumferentially corrugated paving roll having means for engaging it in rolling and supporting contact with the pavement, whereby the auxiliary circumferentially corrugated roll may support one end of the paving roller and thereby crush and spread the paving material laterally, and when raised will permit the smooth paving rolls to act upon the pavement material and smoothen' it.

The invention further consists in the several novel features hereinafter fully set forth and claimed. I

The invention is clearly illustrated in, the drawing accompanying this specification in which Figure 1 is a perspective view of a paving roller embodying a simple form of the present invention;

Fig. 2 is a detail vertical cross section taken through a fragment of the circumferentially corrugated paving roll and Fig. 3 is a diagrammatic view illustrating one "form of means for controlling an auxiliary corrugated paving roll embodying the present invention.

Referring to said drawing, the reference character 5 designates the main frame of a tandem paving roller of conventional form having the usual smooth rolls 6 and 7 and a power plant 8 for driving the roll 6. The steering roll 7 is rotatably mounted in a sadle 9 which is swiveled to the supporting frame 5 on a vertical axis and provided with suitable steering means 10 for the roll 7. The power plant for the paving roller may be of any of the common and well known gasoline or steam types, as is well understood.

A circumferentially corrugated roll is seen at 11 and may comprise one of the rolls 6 or 7 if desired, but in order to obtain certain results, it is preferred that the corrugated roll be in the nature of an auxiliary roll capable of being pressed into rolling engagement with the pavement material or raised there from. In the drawing, the corrugated roll is shown in the form of an auxiliary roll rotatably mounted in two levers, one of which is seen at 12 in ,Fig. 1 fulcrumed upon the saddle 9, as at 13, and having suitable power means for swinging the levers 12 upon thelr fulcrum and therewith moving the auxiliary roll into engagement with the pavement or raising it up therefrom.

As shown in the drawing, the means for operating the corrugated roll comprises a ram 14 mounted upon a bracket 15 secured to the saddle 9 and operatively connected with the levers 12. Conveniently, the ram 14 comprises a cylinder 16 and a plunger 17 reciproeating therein and having a stem 18 which- 2 projects down through the lower end of the cylinder and is secured to a cross bar 19, the ends of which are connected by links 20 to levers 21 fulcrumed. upon the saddle 9 and connected to the levers 12 b links 22. It will be observed that downward movement of the plunger 17 causes downward movement of the corrugated roll 11, whereby it may be moved into rolling contact with the pavement material and that upward movement of connected by a pipe 26 to a pressure tank 27 in sageway which the pump builds up pressure and from which leads a pipe 28 to a four-way valve 29 which controls the movement of the liquid from the pum 23 to the ram 14 and back to the reservoir 5.

Any suitable type of valve may be employed whereby the liquid under pressure may be admitted to the top and bottom of the cylinder 16 and discharged therefrom. As shown, the valve 29 has a valve chamber 30 in which is a slide valve 31 containing ports 32 and 33 which are adapted to control the passage of liquid through the valve. The ports 32 are adapted to register with passageways 3 an 34 that lead to pipes 35 and 36 wh' respectively to the top and bottom of the cylinder 16 of the ram. The port 33 is adapted to establish communication between either passageway 34 and 34 and a discharge pas- 37 from which leads a return pipe 3 that runs to the reservoir 25. a The pipe connects the pressure tank 27 with the slide valve 31.

Check valves 39 are provided at the ports 32 of the slide valve, whi h check valves open towards the passageways 34' and 34, thereby pprmitting ,the liquid under pressure to pass om the. slide valve to the passageways and 34, but preventing the return of the li uid from said passageways into the interior of the slide valve. a rod 40 extending out through the casing of the valve 29 and any suitable lever may be provided for actuating the rod to control the operation of the valve.

When the valve is in the neutral position, as shown in Fig. 3, liquid under pressure is admitted to both sides of the plunger 17, and, consequently, the pressure on both sides of the plunger is balanced. valve towards 3, communication between the discharge pas- A slide valve is moved to the le present invention, after the d is first rolled over th The slide valve 31 has By moving the. the right, as viewed in Fig.

sage 37 and-the passage 34" is established through the port 33, thereby permitting'liqu d contained below theplunger 17 to drain back into the reservoir 25, and, at the same time, the pressure on the upper side of the plunger is maintained, there y causing the plunger to be rugated roll moved downward'u on the paving material. By applying s cient pres-- sure, thesteering roll 7 is raised above the paving material, whereby the weight of that end of the machine is borne by the corrugated paving roll 11. To raise the auxiliary roll out of engagement with the pavement, the whereby the liquid is discharged from the upper end of the cylinder and the plunger therein raised by the liquid admitted under pressure to'the lower side thereof.

The corrugationsare in the form of alternating ridges and grooves 41 and 42 extending circumferentially around the cylindrical face of the roll, and when the corrugated roll supports one end of the paving roller, the ridges sink into'the pavement material, thereby crushing the material, and spreading it laterally of the paving roller instead of piling it upin front of the roll. As a result, the paving material is spread and more evenly distributed under the corrugated roll, thereby, eliminating the possibility of any honey-comb structures, cracks or fissures- In the use of a paving roller embodyingiiie material has n spread upon the street or road, the end of the paving roller containing the corrugated roll e material, thereby the same laterall and leaving a after w 'ch the smooth roll is rolled over the corrugated surface, thereby smoothing out the same. When an auxiliary roll is employed, it is depressed into spreading corrugated surface,

8 rolling and supporting contact with the pavseotion of the paveing material, and after a ment material has been treated wlth the corrugated roll, it may beraised, and said secbe observed that when the auxilit. It will it acts as the steering roll 7 iary roll is in use,

of the machine.

I claim as new,

ters Patent:

1. A paving roller having frontand rear and desire to secure by Let-.

smooth paving rolls, an auxilia circumferentially corrugated vertically-1 ad]ustable roll,

adjacent one oi said rolls,

. and power operated mechanism for depressing sald corrumoved downwardand the cor- .tion finished by running the smooth rolls over gated roll into effective contact with the Pine 7 ment upon which the roller rests. 2. A paving roller having two ro cumferentially corrugated roll, and

, a Gil? adjustment means for raising and lowering sai corrugated roll, including a pressure operated ram, and connections. between the ram and. corrugated roll. a

3. A pavin roller having front and rear rolls, an auxl iary circumferentially corrugated roll, means for raising and lowering said auxiliar roll comprising a ram, pres sure means therefor, and operative connections between said ram and the auxiliary roll.

4. A paving roller having front and rear rolls, an auxiliary circumferentially corrugated roll, a hydraulic ram, a cross bar operated by said ram, and operative connections tween said cross bar and auxiliary roll.

5. A paving roller comprising a supporting frame, a driving roll, a steering roll, and a saddle in which said steering roll is j ournaled, said saddle being swiveled to the support ing frame, an auxiliary circumferentially grooved roll, levers in which said auxiliary roll is rotatablymounted, said levers being fulcrumed upon said saddle, a pressure operated ram supported upon said saddle, and operative connections between said ram and levers for raising and lowering said auxiliary roll.

6. A paving roller comprising a supporting frame, front and rear rolls and an auxil- 1ary circumferentially corrugated roll, a hydraulic ram operatively connected to said "auxiliary roll, .a source of li uid under pressure connected to the top an bottom of said am, and a valve for controlling the admission of said liquid to and from said ram. I

7- paving roller comprising a supporting frame, front and rear smooth rolls, an auxiliary circumferentially corrugated roll,

levers in which said auxiliary roll is rotatably mounted, a ram having a piston therein, a cross bar connected to said piston, levers connected to said cross bar and'to the levers which support the auxiliary roll, a source of liquid under pressure connected to the top and bottom of said ram, and valve mechanism for controlling the admission of said liquid to the top and bottom'of said ram and the discharge of liquid therefrom.

HARRY W. LASTER. 

